Chevrolet 70 1969 Series, Shop Manual

Page: 159 / 913

REAR SUSPENSION 4 A - 2 0
9
10
Adjustable Yoke
Boot
Lock Nut
Diaphragm Rod
Snap Ring
Mounting Bracket
Locating Dowel
Chamber Half (Inner)
Diaphragm
Chamber Half (Outer)
11 Vacuum Inlet
12 Diaphragm Nut
13 Plate Washer
14 Diaphragm Plate
(Large)
15 Diaphragm Plate
(Small)
16 Shift Lever
T-3328
Figure 30— Inter-Axle Vacuum Shift Chamber
2. With above parts centered on diaphragm
rod, tighten retaining nut. Stake rod threads to
prevent nut loosening.
3. Install diaphragm and rod assembly into
inner chamber, then position outer chamber over
inner chamber with diaphragm between inner and
outer chambers.
4. Install. six bolts, washers, and nuts attach­
ing two halves of chamber and diaphragm together.
Tighten nuts evenly and securely.
5. Install boot and yoke on diaphragm rod.
INTER-AXLE DIFFERENTIAL
CONTROL VALVE
Inter-axle differential control valve assembly
is used to control air or vacuum at shift chamber
located at rear axle. Valve is located at instru­
ment panel and is removed as previously directed
in this section.
D ISA SSEM B LY (Fig. 31)
1. Using a small drift, drive out fulcrum pin
securing control lever in valve body. Remove lever.
2. Remove cap nut, O-ring, valve spring, and
valve disc from bottom of body.
3. Push against bottom of valve plunger to
remove plunger from top of body. Remove plunger
spring from body and remove O-ringfromplunger.
C L E A N IN G A N D INSPECTION
Wash all metal parts in cleaning fluid. Care­
fully examine small end of plunger which contacts
valve; if any roughness or damage is evident, re-
Instrument Panel
Nam e Plate
Fulcrum Pin
Control Lever
Exhaust Port
Body
Valve Disc
Valve Spring
O-ring
Cap Nut
To Intake Manifold
or Air Tank
12 To Shift Cylinder
13 Plunger Spring
14 Plunger
TPM-9006 -1
Figure 31 -Inter-Axle Differential Lock Control Valve
place plunger. Inspect valve seat in body; if seat
shows wear or damage, replace body. Replace
valve disc if any wear or damage is evident.
Replace valve spring if rusted or corroded.
A S S E M B L Y (Fig. 31)
1. Install new O-ring in groove in plunger and
on cap nut. Coat plunger with grease containing
zinc oxide, then place spring on small end of
plunger, and install plunger and spring in body.
2. Install control lever in body and secure
with fulcrum pin. Stake pin in place.
3. Turn body bottom side up and install valve
disc, valve spring, and cap nut, being sure new
O-ring is in place on cap nut. Tighten cap nut.
4. After installing valve in vehicle, or using
a test hook-up, test valve as previously directed
under "Maintenance on Vehicles."
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L